A social-networking system, which may include a social-networking website, may enable its users (such as persons or organizations) to interact with it and with each other through it. The social-networking system may, with input from a user, create and store in the social-networking system a user profile associated with the user. The user profile may include demographic information, communication-channel information, and information on personal interests of the user. The social-networking system may also, with input from a user, create and store a record of relationships of the user with other users of the social-networking system, as well as provide services (e.g., wall posts, photo-sharing, event organization, messaging, games, or advertisements) to facilitate social interaction between or among users.
The social-networking system may send over one or more networks content or messages related to its services to a mobile or other computing system of a user. A user may also install software applications on a mobile or other computing system of the user for accessing a user profile of the user and other data within the social-networking system. The social-networking system may generate a personalized set of content objects to display to a user, such as a newsfeed of aggregated stories of other users connected to the user.
A/B testing is a standard approach for evaluating the effects of online experiments. A/B testing typically uses randomized experiments with two variants (typically referred to as A and B), which represent the control and treatment in the experiment. Such experiments are commonly used in web development and marketing, as well as in more traditional forms of advertising. In online settings, the objective is typically to determine how changes to the online environment affect user behavior with the environment. The control and treatment groups are compared, which are generally identical except for a single variation that might impact a user's behavior.